A process has been developed which allows for the photolithographically patterning a spring formed on a substrate. An inherent stress gradient in the spring causes a free portion of the spring to bend up and away from the substrate.
Photolithographically generated springs have a variety of uses including providing electrical contact between separate connection pads onto devices. Particularly, the spring is patterned as a spring contact where the anchor portion fixed to the substrate is electrically connected to a first contact pad on the substrate. The free portion compliantly contacts a second contact pad, thereby electrically interconnecting the two contact pads. Thus, in the foregoing the concept of moving a portion of a micro-machined structure out of a plane is used for improving electrical contact between devices.
Another implementation of a structure, which motivates a portion of a micro-machined structure out of a plane of the substrate, is a two-port reflective switch. Such a switch consists of a moveable shutter connected to an electrostatic out-of-plane actuator capable of inserting the shutter in the light path between two optical fibers.